Production of vat dyestuff



5 State of NBW YOIk,

' throne (violanthronehproduce sion of benzanthrone-e.

benzanthrone, and the fusion can be carried gether..with a, reducing a sci b Patented May 4, 1926 UNITED *sTATEs Mme,

DONALD e. noonns AND LLoYn NATIONAL ANILINE & CHEM PORATION or EW YORK.

rnonuc'rioN on via -DYESTUFE: j j,

No Drawing. Application filed July 2 T0011whomitmayconcern:

Be it known that we, DO ALD G. ROGERS and LLOYD O. DANIELS, citizens of the United States, residing at Buffalo, county of Erie, have inventedcertain new and useful Improven'ients in the Preduction of Vat Dyestuff; and We do hereby declare the followin to be a full, clear, and exact description 0? the invention,'such"as it appertains to make and use the same.

This invention relates to im the production of vat dyestuffs, and particu- "larly to tliefdyestufis known df'by the fu thj jcaustic alkali. i

The presentinven-tion iss based upon; --th e discoverythat a greatly reduced amount of caustic'alkali can be used inthe fusion of out in amaterially reduced period of time and with increased yields of asuperior prodnot, by adding to the reaction mixturea suitable inert solvent or diluent, for. example, kerosene or similar petroleum distillate, to-

gent,ifor example, dextrine; I

The invention will be further illustrated by the following specific example, the parts eing by weight:

(potash from A mixture of l00 parts'o f caustic d Ed-parts of mineral oil (obtame {steam distilled kerosene) having a boiling point above 230 Cais'hea-ted 'to 215-2309 10 will enable others skilled in the art to which provements in as dibenzam LS,'OF surname; N-EwYoRx; ASSIGNQRS To roan cone- NY, 1Na', orNnw' YORK, N. 1,4 003- 1921. serial No.-4a2,1 47'.

The d ;rior bri in excellent yields. It is obtained at the end of the fusion, by cooling of themelt with agitation, as. a granular product, which can be readily handled in its further treatment.

The-produ gorit can be usedas an intermediate for the 4 preparation of other dyes. v

:Instead of using mineral oil in the mannor-described in the above example, other ye produced-in way of supe similarly-used, for example, or. coal-tar" fractions or. distillates which ihave mineltiug point below and a boiling point-"at or ahoyej'that of the, temperature "of the. .fusioni'zgjfThef use ofi solvents or ,diluents that; be desired tempera 11in controlling th other petroleum tune 59f Tthe f fusion assist e temperatures Instead of'using dextrine'gas a reducing ns, and'the tempera: ,can 'bevaried to a considerable ghtnessand strength, and is obtained ctfca-n be used itself as adyestufl' suitable inert" solvents or diluents can be to boilhat orfabovo the agents can be similarly;- used, for 'starch, cellulose, and other can invention,ytl1e 'man} mg the ingred1ents,i

antages which the caustic potash 'ease' of temperature reduction or el1m1na- 5 and. to this heated mixture is' gradually 1. "addedwith agitation an intimate mixture 40 tained at this temperature until the reaction control of the process,

tion offrothing during the fusion, ease of recovery ofth e solvent or diluent used, protection ,0f the reaction mass during and subsequent to the reaction by the solvent layer, so Ion as the solvent is left with the product, an the-production of a superior of fi parts of dextrine and 100 parts ofsubbenzanthrone (analyzing 9496% benzanthrone), and the resulting mass mainis complete. The fusion mass is then allowed b'l t to cool Wil agitation to a temperature of 50 C. or lower, and the mineral oil decanted ofi'. Warm water is added to the residue and 45 the resulting aqueous suspension allowed to stand until theremainder of the mineral oil has separated as an upper layer, which is en removed. The dye is then precipitated by heating tgo boiling and blowing air hrough the-aqueous suspension. The precipitated dyeis'then. filtered off and washed free from alkali.

product with increased yield.

In referring, in the accompanying claims,

to a benzanthrone compound, we use this term as a generic .term to include benzant-hrone itself, or a derivative or an analogue thereof.

The term fusion? is also used to refer to the heating of the benzanthrone compound with caustic alkali in the presence of the indiiferent diluent and reducing agent, whether or not actual melting of either or both the benzanthrone compound and alkali, or solution of either or both in the inert diluent, takes place.

Claims:

1. The improvement in the production of a coloring matter known as dibenzanthrone which comprises subjecting benzanthrone to the action of caustic potash at a temperature of about 215230 C. in the presence of mineral oil having a boiling point of about 230 C. and in the presence of a reducing agent. i

2. The improvement in the production of a dyestuif known asdibenzanthrone which comprises subjecting benzanthrone to fusion with caustic potash at a temperature of about 215230' C. in'the presence of a mineral oil havinga boiling point at or above the temperature of the fusion and in the presence of a carbohydrate.

3. The improvement in the method of producing the coloring matter known as .dibenzanthrone which comprises gradually adding anmlxture of benzanthrone and dextrine to a mixture of caustic potash and mineral oil maintained at a temperature of about 215-230 C.

4;, The improvement in the production of a coloring matter known as dibenzanthrone which comprises subjecting benzanthrone to fusion with caustic potash at a temperature of about 215230 C. in the presence of a petroleum distillate having a boiling point a boiling point of about 215230 C., said diluent being a liquid at ordinary temperature.

6. The improvement in the production of a coloring matter known as dibenzanthrone which comprises subjecting benaanthrone to fusion with caustic potash at a temperature of about 215-230 C. in the presence: of a carbohydrate and of an indifferent diluent having a boiling point at about the temperature of fusion, said diluentbeing a liquid at ordinary room temperature.

7 The improvement in the production of a coloring matter known as dibenzanthrone which comprises subjecting benzanthrone to fusion with caustic potash at a temperature of about 215230 C. in the presence of dextrine and of an indifferent diluent having a boiling point at about the temperature of fusion, said diluent being a liquid at ordinary room temperature.

In testimony whereof we aifia our signatures.

LLOYD C. DANIELS. DONALD G ROGERS. 

